Rapids
Topic: Topographical Maps: Relief Representation and Interpretation · NCERT: Class 11, Ch 5 "Topographical Maps"
Meaning
Rapids are stretches of a river where water rushes fast and rough over a steep, rocky bed. They often occur just above or just below a waterfall, where the bed drops in a series of small steps instead of one big fall. On a topographical map, contours cross the stream at wider spacing than at a waterfall, but closer than on the calm river. Rapids make boat navigation difficult.
Example
The Ganga above Rishikesh in Uttarakhand has a long chain of rapids as it leaves the Himalaya. They are well known for river rafting.
Don't confuse with
- Waterfall: at a waterfall, the water drops almost vertically and the contours merge where they cross the stream. At rapids, the drop is spread out and the contours stay separate.